The present invention relates to the production of a tubular laminated structure, and more particularly to the production of a structure comprising layers of fibrous material, superposed in axial direction, each layer extending from the inside surface to the outside suface of the structure.
The field of application of the invention is, more particularly but not exclusively, that of the production of fibrous structures of reinforcement constituting preforms for producing pieces in composite material, such as for example ablative thermal protection for solid propellant rocket motors.
Various processes are already known for producing reinforcing preforms for axi-symmetrical pieces in composite material.
One of these processes consists in stalking rings of fibrous material and optionally bonding them together, for example by needling, in order to produce a preform which is thereafter densified to obtain the desired axi-symmetrical piece. This process is suitable for producing pieces of relatively small thickness, such as brake discs, but it is no longer adapted when the pieces to be produced have a greater axial dimension.
Another process consists in winding on a mandrel yarns, tapes or strips of fibrous material in superposed layers. The layers may be bonded together in different ways, such as needling or sewing, or else by means of pins implanted on the surface of the mandrel, either so as to actually constitute radial bonding elements, or to provide a passage for radial reinforcing elements which are inserted after the winding operation.